Mould for making an article with a branch pipe by the electroslag remelting process

ABSTRACT

A mould for making an article with a branch pipe by the electroslag remelting process comprises in combination parts to form the body and the branch pipe of the article, respectively, whose walls are provided with passages for a cooling agent. A pipe connection to supply the cooling agent to a passage provided in the wall of a part to form the branch pipe of the article, is disposed in the area adjoining the part to form the article body, wherein a consumable electrode is located. A pipe connection to withdraw the cooling agent from the pasage provided in the wall of a part forming the branch pipe, is disposed at the end of the part, which is remote from the electrode.

Medovar et al. 1 July 1, 1975 [5 MOULD FOR MAKING AN ARTICLE WITH [51]Int. Cl 822d 27/02 A BRANCH PIPE BY THE ELECTROSLAG [58] Field of Search164/52, 126, 128, 252,

REMELTING PROCESS Inventors: Boris lzrailevich Medovar, Bulvar LesiUkrainki, 2, kv. 8; Iiya Iosifovich Kumysh, Vozdukhoflotsky prospekt,42, kv. 51; Georgy Alexandrovich Boiko, ulitsa Vladimiro Lybedskaya, l6,kv. 106, all of Kiev; Volf ludovich Rabinovich, ulitsa Gagarina 74, kv.27, Chekhov Moskovskoi oblasti; Alexandr Ivanovich Sapozhnikov, ulitsaMosfilmovskaya 17/25, kv. 63, Moscow; Georgy Sergeevich Marinsky, ulitsaTatarskaya, l, kv. 9, Kiev; Jury Nikolaevich Kriger, ulitsaOktyabrskaya, 38, kv. 59, Chekhov Moskovskoi oblasti, all of U.S.S.R.

Filed: Mar. 6, 1973 Appl. No.: 338,570

Foreign Application Priority Data Mar. 7, 1972 U.S.S.R 1754963 US. Cl164/252; 164/348 [56] References Cited UNITED STATES PATENTS 2,388,97411/1945 Hopkins 164/52 3,598,175 8/1971 Olsson 249/81 X PrimaryExaminer-Francis S. Husar Assistant Examiner-John E. Roethel Attorney,Agent, or Firm-Holman & Stern [5 7] ABSTRACT A mould for making anarticle with a branch pipe by the electroslag remelting processcomprises in combination parts to form the body and the branch pipe ofthe article, respectively, whose walls are provided with passages for acooling agent. A pipe connection to supply the cooling agent to apassage provided in the wall of a part to form the branch pipe of thearticle, is disposed in the area adjoining the part to form the articlebody, wherein a consumable electrode is located. A pipe connection towithdraw the cooling agent from the pasage provided in the wall of apart forming the branch pipe, is disposed at the end of the part, whichis remote from the electrode.

3 Claims, 3 Drawing Figures MOULD FOR MAKING AN ARTICLE WITH A BRANCHPIPE BY THE ELECTROSLAG REMELTING PROCESS BACKGROUND OF THE INVENTIONThe present invention relates to a mould employed in an electroslagremelting process to make articles having branch pipes, for instance.bodies of high-pressure vessels and closing fittings or valves.

Such power engineering fittings are growing in demand because of a highgrowth rate of the power engineering, putting into operation of a greatnumber of large-size power-engineering units, and because of a necessityto improve the performance of the powerengineering equipment and tocurtail its cost.

A mould used in the electroslag remelting process for making articleshaving a branch pipe is known in the prior art, the mould comprising incombination parts to form the body and the branch pipe of an article,respectively; the parts are provided with walls having passages completewith pipe connections to effect the supply and withdrawal of a coolingagent flowing through the passage upwardly in the direction of an ingotbeing built up (cf. the book entitled Special Electric Metallurgy" (inRussian), USSR, published by Naukova dumka", reports of theInternational Symposium on Special Electric Metallurgy, Kiev, June 1972,Part 1, pages 173-174, FIGS. 1 and 2).

This mould enables one either to make the body simultaneously with thebranch pipe or to fuse in the course of the electroslag remeltingprocess to the former prefabricated cast or forged branch pipe stock.

However, only branch pipes 100 to l50 mm long can be made simultaneouslywith the body in such moulds. Yet in practice, when assembling thearticles with branch pipes, it is desirable to employ the pieces havingelongated branch pipes.

Attempts were made to manufacture an article having an elongated branchpipe by extending the part of the mould intended to form the branchpipe. Those at tempts did not produce favorable results since thesurface of such a branch pipe exhibited defects resembling tocorrugations.

These defects reduce the constructive strength of the branch pipe; thatis why the branch pipes will have to be made thickened with thesubsequent removal of the portions exhibiting those defects. The removalof the defects from the surface of those branch pipes by mechanicalmeans leads to metal losses, so as to the use of additional epuipment,and waste of labor. The formation of the aforementioned defects resultsfrom the fact that in the mould of the prior-art design the supply andwithdrawal of the cooling agent to and from the passages provided in thewalls of the parts forming the branch pipe of the article is embodiedwithout taking into account the temperature gradient in the molten slagand metal baths along the branch pipe to be formed.

Moreover, the part of the mould forming the branch pipe of the article,is embodied with the walls of the same thickness along the entire lengthof the branch pipe, in which there is provided a continuous annular gapor passage providing for the uniform withdrawal of heat throughout theentire length of the branch pipe to be formed, while the portion of thisbranch pipe adjoining the melting zone of a consumable electrode (orheat-evolution zone) receives a greater amount of heat than the portionof the branch pipe, which is remote from the consumable electrode. Thatis why the temperature of the baths of molten metal and slag lowers inthe direction from the consumable electrode heat source to the free endof the branch pipe. Consequently, to improve the solidificationconditions of the article branch pipe requires a non-uniform withdrawalof heat; namely, a greater amount of heat will have to be withdrawnwithin the heat-evolution zone, and a smaller amount of heat, within theportion of the branch pipe which is remote thereof.

The non-observance of these conditions is likely to create difficultiesinterfering with the manufacture of the branch pipes of a specifiedlength having a goodquality surface.

SUMMARY OF THE INVENTION The primary object of the present invention isto provide a mould to be used in the electroslag remelting process formaking an article with a branch pipe, for instance bodies of vessels orclosing fittings, such as valves, dampers, shutters, etc., which wouldenable a branch pipe of a specified length to be cast.

Another, not less important, object of the invention is to improve thequality of the branch pipe surface throughout its length by obviatingthe formation of defects like corrugations on the surface thereof.

A still further object of the invention is to reduce the consumption ofmetal as may be caused by eliminating the defects on the branch pipesurface through mechanical treatment, and to dispense with the laborexpenses involved therein.

While a preferred embodiment of the invention will be describedhereinbelow, it will be understood that one skilled in the art may makevarious modifications in the mould without departing from the spirit ofthe invention and the scope of the appended claims.

These and other objects of the invention have been accomplished by theprovision of a mould to be employed in the electroslag remelting processfor making an article with a branch pipe, which comprises in combinationparts to form the body and the branch pipe of the article, respectively,in whose walls there are provided passages complete with pipeconnections for the supply and withdrawal of a cooling agent, in which,in accordance with the invention, the pipe connection to supply thecooling agent to the passages in the part forming the branch pipe of thearticle, is disposed within its area adjacent to the part forming thearticle body within a zone wherein a consumable electrode is located,whereas the pipe connection serving to withdraw the cooling agent fromthe passages, is disposed at the remote end of the part forming thebranch pipe of the article.

Such a design of the mould part forming the branch pipe of the article,v creates a directed flow of the cooling agent from the portions of theslag and metal baths having a higher temperature to their portionshaving a lower temperature. Under these conditions, the more remoteportions of the branch pipe will be cooled by the cooling agent raisedat a higher temperature as compared with the portions adjacent to theheatevolution zone.

It would be advisable to make the mould in such a manner that the wallsof its part forming the branch pipe of the article will grow thicker inthe direction of the remote end of that part.

This will allow an increase in the temperature of the portions of theslag and metal baths that are disposed at the remote end of the branchpipe.

The mould part forming the branch pipe of the article may be providedwith a passage following a helical line whose pitch progressivelyincreases in the direction of the remote end of that part.

This will allow a reduction in the amount of heat to be withdrawn fromthe portions of the slag and metal baths disposed at the free end of thebranch pipe.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be describedfurther in detail and by way of example with reference to theaccompanying drawings, in which:

FIG. I is a view of the mould according to the present invention insection along the longitudinal axis of the parts forming the body andthe branch pipe of an article to be made by the electroslag remeltingprocess;

FIG. 2 is a cross-sectional view along the line II-ll of FIG. I; and

FIG. 3 shows the mould complete with a part to form the branch pipe, inwhose walls there is provided a helical passage having a variable pitch.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIGS. 1 and2, the mould suitable for use in the electroslag remelting process formaking an article having a branch pipe comprises in combination parts 1and 2 to form the body and the branch pipe of the article, respectively.The part 2 forming the branch pipe of the article has in its wallspassages 3 for a cooling agent, the passages being interconnectedthrough collectors 4 and 5. A pipe connection 6 is intended forsupplying the cooling agent to the collector 4 and passages 3, and isdisposed within an area adjacent to the part 1 forming the body of thearticle, near the zone wherein a consumable electrode 7 is located. Apipe connection 8 is intended for the withdrawal of the cooling agentfrom the collector 5, and is disposed at the remote free end of the part2 forming the branch pipe of the article. The consumable electrode 7 islocated in a gap between the mould part 1 forming the article body, anda core 9 serving to form the hollow of the article. The consumableelectrode 7 is immersed into a bath 10 of molten slag, below which thereare disposed a bath 11 of molten metal and solidified metal 12 of thearticle being made. The part 2 forming the branch pipe of the articlehas its walls 13 embodied such as to grow thicker in cross section inthe direction of the free end of the branch pipe ('6, 8

In another embodiment of the part 2 forming the branch pipe of thearticle, as shown in FIG. 3, a passage 14 for the cooling agent is madein the form of a helical line whose pitch progressively increases in thedirection of the free end of the branch pipe.

The mould of the invention operates in the following manner. A batch ofmolten slag is poured into a gap available between the core 9 (FIG. 1)and the mould part I forming the body of the article being made. As

the article is built up, the slag bath and the metal 1511mm rise andfill up the hollow provided in the A 'mould 'part' Ziorrning the branchpipe of the article being made. The cooling agent arrives in this part 2through the inlet pipe connection 6 and the collector 4 to the passages3, then to the collector 5, and flows out from the pipe connection 8.

The cooling agent flows in a similar manner through n the helicalpassage 14 (FIG. 3) from the pipe connections 6 to the pipe connection8.

In both cases the cooling agent having a lower temperature first of allcools down the portions of the branch pipe that are disposed nearer tothe zone of 15 melting the consumable electrode 7 and that are exposedto a more intense heating. Thereafter, the cooling agent having beenpreheated on the aforesaid portions, is supplied to the portions thatare more remote from the consumable electrode 7 and are raised to atemperature lower than that of the molten metal and slag. The coolingagent absorbs the heat from those portions less intensely, and theportions of the metal and slag baths found therein will not beovercooled, which will contribute to equalizing the temperature of metalsolidifying into the branch pipe throughout its length.

As it has been proved by testing, the described mould is suitable tomake by the electroslag remelting process a good quality article with abranch pipe about 400 mm long.

We claim:

1. A mould to be used in an electroslag remelting process for making anarticle with a branch pipe, which comprises in combination: a first parthaving walls to form a body of the article; a second part having wallsto form the branch pipe of the article and having a portion thereofdisposed adjacent to said first part forming the body of the article;passages for a cooling agent being disposed in said walls of said firstand second 40 parts forming the body and branch pipe of the article; afirst pipe connection to supply the cooling agent into said passagesdisposed in said walls of said second part forming the branch pipe ofthe article, the pipe connection being disposed within an area adjacentto said first part forming the body of the article in a zone wherein aconsumable electrode is located; and a second pipe connection towithdraw the cooling agent from said passages disposed in said walls ofsaid second part forming the branch pipe said second pipe connectionbeing further disposed at the remote end thereof.

2. A mould as of claim 1, wherein said second part forming the branchpipe of the article has its walls made to become thicker in crosssection in the direction of the remote end of said second part.

3. A mould as of claim 1, wherein said second part forming the branchpipe of the article is provided with a passage made as a helix having apitch which increases in the direction of the remote end of said secondpart. 60 I! l l l

1. A mould to be used in an electroslag remelting process for making anarticle with a branch pipe, which comprises in combination: a first parthaving walls to form a body of the article; a second part having wallsto form the branch pipe of the article and having a portion thereofdisposed adjacent to said first part forming the body of the article;passages for a cooling agent being disposed in said walls of said firstand second parts forming the body and branch pipe of the article; afirst pipe connection to supply the cooling agent into said passagesdisposed in said walls of said second part forming the branch pipe ofthe article, the pipe connection being disposed within an area adjacentto said first part forming the body of the article in a zone wherein aconsumable electrode is located; and a second pipe connection towithdraw the cooling agent from said passages disposed in said walls ofsaid second part forming the branch pipe said second pipe connectionbeing further disposed at the remote end thereof.
 2. A mould as of claim1, wherein said second part forming the branch pipe of the article hasits walls made to become thicker in cross section in the direction ofthe remote end of said second part.
 3. A mould as of claim 1, whereinsaid second part forming the branch pipe of the article is provided witha passage made as a helix having a pitch which increases in thedirection of the remote end of said second part.